注册广播的方式有两种：在代码中动态注册，或是在AndroidManifest.xml中进行静态注册。

如果想要创建一个广播接收器，新建一个类，继承自BroadcastReceiver，并且继承父类的onReceive()方法。

package com.broadcasttest.lightless.broadcasttest;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;


public class MainActivity extends Activity {

    private IntentFilter intentFilter;
    private NetworkChangeReceiver networkChangeReceiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        intentFilter = new IntentFilter();
        intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
        networkChangeReceiver = new NetworkChangeReceiver();
        registerReceiver(networkChangeReceiver, intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(networkChangeReceiver);
    }

    class NetworkChangeReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(context, "network changes", Toast.LENGTH_SHORT).show();
        }
    }


}

如果使用内部类，必须将自己的Receiver定义为static。
在AS中，如果要使用本地广播（LocalBroadcastManager），必须要在File->Project Structure中的Dependencies中引入support-v4这个东西。